Long stroke plunger for deep drawing plunger press



Nov. 28, 1961 A. T. PETERSON LONG STROKE PLUNGER FOR DEEP DRAWING PLUNGER PRESS Filed Feb. 3, 1960 3 Sheets-Sheet l ooooooaco5 mmmmmmmm ES QEEEQQE J INVENTOR. HRV/D 7T PETERso/v HTTORNEY Nov. 28, 1961 A. T. PETERSON LONG STROKE PLUNGER FOR DEEP DRAWING PLUNGER PRESS 5 Sheets-Sheet 2 Filed Feb. 3, 1960 SEE- HR we 7. PETERSON HTTORNEY LONG STROKE PLUNGER FOR DEEP DRAWING PLUNGER PRESS Filed Feb. 3, 1960 Nov. 28, 1961 A. T. PETERSON 3 Sheets-Sheet 3 OF RHM STROKE.

HTT RNEY United States Patent (3 V 7 3,010,415 LONG STROKE PLUNGER FOR DEEP DRAWING PLUNGER PRESS Arvid T. Peterson, Sarasota, Fla., assignor, by mesue assignmeuts, to The Waterbury Farrel Foundry & Machine Co., Division of Textron Inc., Waterbury, Conn.

Filed Feb. 3, 1960, Ser. No. 6,559 11 Claims. (Cl. 11340) This invention relates to multiple plunger presses and eyelet machines, and more particularly to a machine of the above nature having a plurality of sets of cooperating drawing punches and dies in which the drawn shells are automatically transferred successively from station to station, and whereby a constant stream of completed shells will flow from the machine when it is in operation.

A further object is to provide a heavy duty plunger press of the above nature in which the drawing plungers are simultaneously driven on their down strokes by a plurality of cams mounted on a single overhead rotating cam shaft.

A further object is to provide a machine of the above nature in which the upward strokes of the drawing plungers are produced by lifting cam mechanisms in such a manner as to produce a rest period in said strokes during which the transfer mechanism may grip the various shells and move them into alignment with the plungers at the next stations.

A further object is to produce an improved form of plunger for a machine of the above nature, having means to increase the length of travel of some of said plungers by approximately one-third over the plungers of previous eyelet machines. f

A further object is to provide a machine of the above nature having a special long stroke plunger which may be installed in any desired station of said machine without changing any of the other parts thereof.

Afurther object is to provide an improved plunger press or eyelet machine in which the waste motion of the standard plunger is avoided and the plunger is permitted to go into operation more quickly during the down stroke thereof. 1'

A further object is to provide an improved plunger for a machine of the above nature including a pair of pivotally connected upper and lower links pivotally mounted in a slot in said plunger, the lower link being connected to the punch and the upper link being adapted to engage a cam block mounted on the frame of the machine in such a manner as to cause said links to assume a straight line position so that the punch will engage the shell being operated upon with a powerful toggle action.

A further object is to provide a machine of the above nature which will be relatively simple in construction, inexpensive to manufacture, easy to install and manipulate, compact, ornamental in appearance and very eflicient and durable in use.

With these and other objects in view there has been illustrated on the accompanying drawings one form in which the invention may conveniently be embodied in practice.

In the drawings,

FIG. 1 represents an assembly view of an eyelet machine on which an improved deep drawing plunger has been installed at one station thereof.

FIG. 2 is a vertical cross-sectional view through the improved deep drawing plunger embodying the invention.

FIG. 3 is a detail cross-sectional view of the improved plunger shown in its uppermost position, prior to the downward stroke thereof.

FIG. 4 is a similar cross-sectional view of said improved plunger, shown in an intermediate position.

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FIG. 5 is a view similar to FIGS. 3 and 4, showing the improved long stroke.plunger in its lowermost or drawing position.

FIG. 6 is a cross-sectional view taken along the line 6-6 of FIG. 3.

FIG. 7 is a cross-sectional view taken along the line 7-7 of FIG. 5.

FIG. 8 is a cross-sectional view taken along the line 8-8 of FIG. 3.

FIG. 9 is a vertical sectional view taken along the broken line 9-9 of FIG. 5.

Referring now to the drawings in which like numerals denote corresponding parts throughout the several views, the numeral 10 indicates the base of a multiple plunger eyelet machine, on which is mounted a frame 11 carrying a horizontal cam shaft 12, the latter having a plurality of plunger-depressing cams 13 secured thereto by keys 12a, said cams being adapted to engage a plurality of rollers 15 (see FIG. 2).

The rollers 15 are carried by boxes 44, the lower portions of which engage the heads 47 of the standard plungers 46 and also engages the head 47 of a special long stroke plunger 46a.

Provision is also made for a plurality of plunger lifting cams 14 mounted on the cam shaft 12, which are adapted to engage the horizontal lifter arms 16. Each of the horizontal lifter arms 16 (FIGS. 1 and 2) is adjustable and secured to a vertical lifter rod 17 by means of a clamping screw 18.

Each of the lifter rods 17 is provided upon its top end with a book 20 attached to a vertical balancing coil spring 19, the upper end of which (as shown in FIG. 1), is secured to a top hook 21 having a threaded upper end which passes through a U-frame 22, and is secured thereto by adjusting nuts 23. I a

At the center of the U- frame 22, provision is made of a vertical support rod 24, connected at its bottom end with the frame 11, and to the top of the U-frame 22 by nuts 25, 26 screwed on the upper end of said rod 24.

The cam shaft 12 is driven by a drive gear 27, which receives power from a pinion gear (not shown) located behind the drive gear 27. A pinion drive shaft 28:: is also provided and has a flywheel 28 connected to a clutch 29, said flywheel 28 being provided with a plurality of parallel grooves engaged by a plurality of V-belts 31, which receive power from a pulley 32 driven by a motor 33 mounted upon a horizontal section 37 of the base 10, as clearly shown in FIG. 1 of the drawings. Provision is also made of an outboard bearing arm 34 upon which is mounted a brake 35 carried by a horizontal shaft 36.

In order to provide a friction bearing for each lifter rod 17, provision is made of a plurality of bronze woodlined friction rings 38 (see FIG. 2), which are mounted on a plurality of depending arms 39 secured to the frame 11. The tightness of each friction ring 38 against its lifter rod 17 is controlled by a pair of horizontal screws 40 and 41, each of which is embraced by a coil spring 42.

Provision is also made of vertical bolts 43 for attaching the arms 39 to the frame 11. The roller carrying box 44 is mounted in a horizontal connecting arm 45 which is rigidly attached to the lifting rod 17 in any suitable manner. Each plunger 46 and 46a is provided with a flat upper head 47 seated on the connecting arm 45.

The front of frame 11 is provided with a plurality of caps 50 secured to said frame by horizontal screws 50a. Provision is made for felt lubricating pads 48 and brass supporting plates 49 which surround the plungers 46, 46a and are mounted on the two caps 50 of the frame 11.

The numeral 51 indicates a vertical slot in the special improved long stroke plunger 46a, said slot terminating at its lower end in a hollow bottom section 52 (see FIGS.

8 and 9), within which is a sliding cylindrical member 52a having at its bottom end a tapped hole 52b for receiving a punch 54' having a threadedupper end 55. The punch 54 is also provided with ahexagonal ,nut section 356. The upper end of the sliding member 52a has a slot 520 for embracing the lower end of a straight bottom link 58 which is attached thereto by a horizontal pin 61;

Provision is also made in the special plunger 46a of an upper angular link 57 which is slotted at '62 to embrace the lower link 58. The upper ling '57 is secured to the plunger 46a by a pin 59, and said links '57 and 58 are secured together by a pivot pin '60.

Provision is also made of a cam block 63 rigidly secured to the frame 11 of the machine, said cam block having a hardened concave top insert 64, as shown more clearly in FIGS. 3, 4, and 5. The bottom of the cam block 63 isprovided with a separate detachable cam piece 65 having a convex surface 66.

The link 57 is provided with an upper angular end portion 69 and the cam block 63 is provided with a vertical surface 67 which is adapted to engage said upper portion 69 to maintain'said link in the straight toggle position, shown in FIG. 5. The link 58 has "opposite straight side surfaces as indicated by the numerals 70 and 71. Provision is also made of a hollow bearing cavity 68, by which the lower portions 70 and 71 of the link 58 are laterally supported, as clearly shown in FIG. 5.

Operation -In the operation of this machine, the plungers 46, 46a will be continually reciprocated by the operation of the cams 13 and 14. On the downstroke of the plunger 4612, the upper link 57 will be rotated in a counterclockwise direction by the action on said link of the stationary cam block 63 and the convex; surface 66. The counterclockwise rotation of the link 57 about the pin 59 will cause the connecting pin 66 to move in an arcuate path toward the axis of the plunger 46a, thereby moving the link 58 pivoted about the pin 61 in a clockwise direction until the links 57 and 58 form a substantially straight line, or more accurately the pin 60 is slightly to the right of the axis of the links 57 and 58 in a locked position. These links are locked in a substantially straight line by the combined action of constraining lateral movement of the link 58 by having the surfaces 70, 71 of said link confined by the bearing surface 68, and constraining the movement of the'link 57 in a clockwise direction by the abutting surface 67 of the cam block 63 and the upper portion 69 of the link 57. The sequence of operations just described can be seen in FIGS. 3, 4, and respectively. The toggle action of the links 57, 58 will then cause'the punch 54 of the plunger 46a to engage the shell to be more deeply drawn, due to the stroke elongation of said plunger.

On the upstroke of the plunger 46a, the upper link 57 will engage the concave insert 64 of the stationary cam block 63 to break the substantially straight line toggle by causing the link 57 to rotate clockwise, and the pin 60 to move to the left, thereby rotating the link 58 in' a counterclockwise direction. This action is just the reverse of that described in the preceding paragraph, and results in withdrawing the punch 54 an equal distance from the shell. A coil of metal fed from a reel in the front of the first of the plungers 46 will pass over the first die and be wound on a scrap reel at the rear of the machine. The timing of the machine is such that the transfer slide motion is momentarily suspended while the punches descend into their respective dies.

After each drawing operation the plungers will be raised to clear the transfer slide which will then carry the blanks into line with the next succeeding plungers.

This cycle is repeated with every revolution of the cam shaft, so that the shells willbe progressively drawn in their successive dies. One part will thus be completed with 4 every stroke of the eyelet machine and delivered through a tube to a'receptacle on the floor.

It will be understood that the upward motion of the plungers 46 and 46a will be effected in all cases by the lifter cams 14 which operate against the horizontal lifter arms 16. These arms are adjustably attached to the lifter rods 17, which slide in the bronze friction bushings 38 in the frame, the lifter rods being rigidly joined to their respective plungers. The stroke of each plunger can be readily'adjusted for various lengths of shells. 7

When the machine is installed in place and completely assembled it should be thoroughly lubricated prior to operation. The plungers and lifter cams will customarily be lubricated by cam tassles saturated by a mixture of white lead and 'oil.

Advantages One advantage of. the present invention is that the improved long-stroke plunger may be installed at my station of a multiple plunger press or eyelet machine, without any other change being necessary in the existing machine.

In one example of such an improved machine, a punchcarrying plunger which normally travels 3 inches was changed to a long-stroke plunger having 4 /2 inches of travel.

Another advantage is that each of the improved long stroke plungers herein disclosed may be adjusted individually to suit the lengthof the shell being drawn, and the punches or tools may be changed quickly and easily at each station, independently of the other stations.

A further advantage is that a smaller size eyelet inachine may be used for a given operation, with the attendant greater speed of the motor drive permitted, and consequently increased production may be achieved.

While there has been disclosed in this specification one form in which the invention may be embodied, it is to be understood that this form is shown for the purpose of illustration only, and that the invention is not limited to the specific disclosure, but may be modified and embodied in various other equivalent forms without departing from its spirit. In short the invention includes all the modifications and embodiments coming within the scope of the following claims.

Having thus fully described the invention, what is claimed as newand for which 'it is desired to secure Letters Patent is:

1; 'In a plunger press, a frame, a punch, a' punchcarr ying plunger mounted to reciprocate Vertically in said frame, a die, a die carrying bed supported by said frame, means to drive said plunger downwardly for causing said punch to engage a shell carried by said die, means to retract said plunger upwardly to withdraw said punch out of said die, said plunger having a pair of upper and lower toggle links which. are pivoted together and to said plunger, and mounted in an elongated slot in the lower end of said plunger, said punch being secured to said lower link, and cam means rigidly secured to said frame contacting a portion of said upper link and causing said upper link to rotate, thereby forcing said links from a position at an angle to each other to a straight line toggle position, whereby the effective length of said plunger will be increased during its downward stroke and said punch will be caused to travel farther than the plunger which supports it.

2. The invention as defined in claim 1, in which the lower link is connected to a slide member located within said plunger, and to whichthe operating punch is adjustably attached.

3. The invention as defined in claim 1, in which said upper link is angular in shape.

4. The invention as defined in-claim 3, in which said cam means comprises a block having a concave upper section in alignment with Said angular upper link, to cause the lower end of the latter to move into an inclined position when'said plunger is moved upwardly.

5. The invention as defined in claim 4, in which said cam means has a convex lower section in alignment with the upper end of said upper angular link and constrained to move said upper link in a direction when said plunger is moved downwardly to cause said links to assume a straight line toggle position.

6. The invention as defined in claim 1, in which the lower end of said upper link is angular and bifurcated to embrace the upper end of the lower link pivoted thereto.

7. The invention as defined in claim 4, in which the concave upper section of said cam is hardened to increase the wear resistance thereof.

8. The invention as defined in claim 5, in which said convex lower section of said cam block is detachable therefrom.

9. The invention as defined in claim 3, in which said convex lower section of said cam block has a straight vertical portion which engages the upper end of said angular upper link when said plunger is at the bottom of its stroke to positively hold the lower portion of said upper link and said lower link in its straight line toggle position and permit the shell to be deeply drawn due to the stroke elongation of said punch.

10. The invention as defined in claim 1, in which said 6 frame is provided with a hollow bearing cavity which serves to laterally support the lower portion of the lower toggle link to assist in maintaining said links in their straight line toggle position when said plunger is at the bottom of its stroke.

11. The invention as defined in claim 1, in which the lower section of said cam block has a straight vertical portion for engagement with the upper end of said upper toggle link, and said frame is provided with a hollow bearing cavity which serves to laterally support the lower portion of the lower toggle link, to positively maintain said links in a straight line toggle position when said plunger is at the bottom of its stroke to cause said shell to be deeply drawn due to the stroke elongation of said punch.

References Cited in the file of this patent UNITED STATES PATENTS 156,651 Safiord Nov. 10, 1874 1,952,195 Candee et a1 Mar. 27, 1934 2,275,681 Pierson Mar. 10, 1942 FOREIGN PATENTS 554,143 Great Britain June 22, 1943 

